Imagine that you're at dinner with some very bright friends who like to draw fascinating and seemingly unlikely connections between various events. You may argue with them and concede different points and yet your overall reaction will be pure pleasure.

SuperFreakonomics is great fun for those of us who believe in the law of unintended consequences. Push in here and look for the reactions elsewhere. Levitt and Dubner discuss a collection of connections. Which was safer? A New York City filled with automobile traffic or one where horses were the chief mode of transportation? (Go with the cars.) Why may patients of the better doctors have a higher death rate? With all things being equal, who is more likely to gain tenure, professor Albert Aab or professor Albert Zyzmor? How do the habits of some prostitutes resemble department store Santas? What were the effects of the September 11 attacks on traffic fatalities? On the spread of flu? On investigations of the Mafia?

The book is a grand exercise in looking for the unintended, in considering how what may seem positive or negative can have the opposite effect. It should serve as a caution to those reckless souls who believe in grandiose plans. Levitt and Dubner would say, "Be careful. You might just get what you asked for."